What you are leaving out of these equations is spending. Contrary to popular belief that Regan slashed spending it grew at a large pace. Just as spending has pretty much since. Reagan's tax cuts ushered in an economic boom in the '80's that went for over a couple of decades.
First, I am not going to indulge you in pretending that we have not heard over an over for three decades the rightwing mantra "Tax cuts pay for themselves!"
Second, George Dumbya and Donald Trump did not propose and enact massive spending cuts in concert with their tax bills, to make it all balance out. So the "coulda, woulda, shoulda, if, maybe, perhaps" hypothetical argument just does not cut it...it is moot at best...an exercise in abject excuse-making at worst.
I am not going to argue that there was significant economic, if totally uneven, economic growth in the 1980s. The investor class, the white collar services industry, the wealthy, and the Pentagon related industries did remarkably well. The working class, the blue collar, the poor, and minorities in general did not see the benefits the investor class did. And I do not accept the premise that Reagan's ill-advised, deficit-causing tax cuts should be hailed as the golden age of fiscal logic. Reagan also wanted, proposed, and got massive spending increases in defense related industries, wars on drugs, and his administration had to spend the last 6 years in office trying to find revenue and raising taxes because of the enormous budget deficits they caused with their 1981 tax cut scheme.
